Data of field activity D-1-96-NC in Gorda Ridge from 07/08/1996 to 08/07/1996

Title:: Data of field activity D-1-96-NC in Gorda Ridge from 07/08/1996 to 08/07/1996
Abstract:: United States Geological Survey, Menlo Park, California,National Oceanic and Atmospheric Administration. Chief Scientists: Kim Klitgord, Bob Embley, Rob Zierenberg. Data (sidescansonar, airgun, gravitycore) of field activity D-1-96-NC in Gorda Ridge from 07/08/1996 to 08/07/1996, <http://walrus.wr.usgs.gov/infobank/d/d196nc/html/d-1-96-nc.meta.html>.
Supplemental_Information:: Equipment Used -
sidescansonar
airgun
gravitycore
Notes -
Leased SSS

from Western Region Marine and Coastal Surveys Bulletin, July 26,
1996...

Good eating (and results) on the Disco
Jane reid sends news from
National Oceanic and Atmospheric Administration (NOAA)'s
<http://www.noaa.gov>
research vessel Discoverer (aka Disco), where
she, Kim Klitgord (co-chief scientist), and about half a dozen other USGS'ers
are cooperating with NOAA in a three-week cruise off the pacific northwest. They
are collecting sidescan-sonar and seismic-reflection data in three areas: (1)
the coaxial segment of the Juan de Fuca Ridge, where a volcanic eruption
occurred in 1993; (2) the northern part of the Gorda Ridge, where a volcanic
eruption occurred in april of this year; and (3) Escanaba Trough (southern Gorda
Ridge), where hydrothermal vents and a thick blanket of sediment have produced
large sulfide deposits analogous to deposits on land.. here is the report Jane
sent last week:

"After some initial problems (non-sinking transponders, sticky winch, and overly
hot sidescan system) we are now getting great sidescan and sub-bottom profiles
over NOAA's floc area of the coaxial segment of the Juan de Fuca Ridge. The
transponder net is well calibrated and the winch is working to fly the towfish
at altitudes of about 160 meters above the bottom. The data looks
wonderful: fault scarps and fissures and lava structures from recent flows.
sidescan images are coming in clear and sharp. Acoustic navigation is
intermittent, but Stuart Sides and Miguel Velasco from Flagstaff have kept up
with the processing and we expect to have a completed mosaic in the next week or
so. After a couple of short deployments and recoveries on the southern part of
the Juan de Fuca, it's off to Escanaba Trough for 8 days of side-scan work
and seismic lines. The weather has been swell, though we expect it to get
sweller (a low is headed our way). The food is excellent. expect some waddling
when we return. What we all need are fewer Haagen Daz bars and more Altoids. "
for more information about vents in the northeast Pacific (and links to pages
about other neat stuff) check out this NOAA page on the world wide web:
<http://www.pmel.noaa.gov/vents/>

from Western Region Marine and Coastal Surveys Bulletin, August 2,
1996...

More news from the Discoverer
The Escanaba part of the survey is collecting great data right now. We have two
excellent NW and two NE trending profiles across the mounds region and are about
to start the third. Great records on the sidescan, 4.5khz, and airgun systems.
the quality is definitely above expectations. Poor fish nav but good ship nav.
25-30 knot winds have delayed us a bit due to difficulty holding courses going
with the wind, so we have had to make some adjustments to acquire the desired
data. Still the prospects for 100% data of the trough, but unless there are
major problems we will have not trouble acquiring all of the primary data in the
mounds vicinity. Seismic data indicate that we may be able to develop a relative
fault age distribution. Rob Zierenberg is thrilled with sidescan images over the
mounds with 1000m swaths at 100m above seafloor. Sulfide mound zones are clearly
visible. NW trending faults coming into the mounds are "very" linear. could not
ask for better images. Very easy to correlate faults and other structures in
the airgun data with features on the deep towed sidescan and 4.5khz data.
sidescan processing is nearly complete for the NOAA Juan de Fuca co-axial region
study and Stuart and Miguel are already working on the Escanaba data. Larry,
Mike, and Tom have a superb seismic reflection profile record coming in. Initial
processing of seismic reflection data is already underway on Tommy's Silicon
Graphics machine, for both airgun and 4.5khz data sets. Swath bathymetric
processing for escanaba is about to start but should be easy by comparison with
the Juan de Fuca data set. Operations are smooth and the whole team is putting
in a great effort. The Williamson team is providing great support.:Kim

Discoverer's good voyage
The Disco is coming into port today, ending the last oceanographic cruise of her
30-year career. If all goes as predicted, she "will be escorted in by a fire
boat, spraying water as we approach the locks into lake union. We're stopping in
Everett to pick up 80 or 100 crew dependents so they can transit the rest of the
way in. We should arrive at the dock on Lake Union about 1:30 p.m. on Friday.
whee!" Jane Reid

Here's a recap on the cruise from Kim Klitgord.
The NOAA-USGS cruise on the NOAA's Discoverer, with Robert Embley (NOAA) and Kim
Klitgord (USGS) as co-chief scientists, has successfully completed its sidescan
sonar studies of the co-axial segment of the Juan de Fuca Ridge (NOAA vents
program) and the Escanaba Trough on the southern Gorda Ridge. The AMS-60
sidescan sonar system and 4.5 khz sub-bottom profiler system leased and operated
by Williamson and associates were used for both surveys. At Escanaba Trough,
nearly 350 km of near-bottom sidescan sonar and 4.5 khz sub-bottom penetration
data and surface towed airgun seismic reflection data were acquired on a grid of
18 lines over the Nesca hydrothermal system within the axial valley of Escanaba
Trough. A tight grid of 1 to 2 km spacing swaths in both the NNW and NE
directions have provided two complete sidescan mosaics with different image
angles for interpreting the surficial geologic character of the 18 km x 25 km
region centered on the hydrothermal mounds that are the drill target for the
ODP leg 169 that starts later this month with Rob Zierenberg (USGS) as co-
chief scientist. Stuart Sides and Miguel Velasco (Flagstaff) have already
completed the sidescan sonar processing and Rob is hopping from the Discoverer
to the Joides Resolution with a set of fantastic mosaics. The 4.5 khz seismic
system routinely imaged over 50 meters below the seafloor and provided a superb
stratigraphic record of the interlinked volcanism, deformation and turbidite
deposition within Escanaba Trough. "z" and Stephahie Ross have been constantly
identifying features on these records that they have found on previous dives,
camera runs, and sampling sorties. Stephanie, Kaye Kinoshita and Jane Reid
(USGS), Bill Chadwick and Julia Getsiv (NOAA), and Jim Fowler (Arizona State)
have kept us tightly navigated, ruled the watches and made sure that all we
found would not be lost. The 160 cu.in. single channel airgun data provided an
excellent image of the entire sediment column and basement structures for the
entire area, at times exceeding 1000 m of penetration. Larry Kooker, Mike Boyle,
Tom O'Brien and Hal Williams were jumping, keeping the airgun and winch systems
fine tuned. Se Won Chang and Hun Soo Choi have become the moguls of
swath-bathymetry mapping, keeping Tommy O's Silicon Graphics workstation
filled with bits and bytes, occasionally bringing it to its knees. The Escanaba
Trough survey revealed a narrow 4-km wide zone of neotectonic activity with the
most active faulting and volcanic activity. The recent basaltic flows provided
bright sidescan targets enabling us to readily map their areal extent and to
identify their likely eruption source: a fissured volcanic hill 2 km east of the
hydrothermal central hill of Nesca. The hydrothermal fields on the central hill
and southwest hill were clearly identifiable. Growth faults in the 4.5 khz data
provide a fine data base for establishing the faulting history within the
neotectonic zone to complement the volcanic history.
Publications -
Ross, Stephanie L., and Zierenberg, Robert A., 2009, Sidescan Sonar Imagery of
the Escanaba Trough, Southern Gorda Ridge, Offshore Northern California:
Scientific Investigations Map 2907, scale 1:25,000. URL:
<A HREF ="<http://pubs.usgs.gov/sim/2907/>" target ="MF"><http://pubs.usgs.gov/sim/2907/>

Similar information is available for thousands of other USGS/CMG-related Activities.
If known, available are Activity-specific navigation, gravity, magnetics, bathymetry, seismic, and sampling data; track maps; and equipment information; as well as summary overviews, crew lists, and information about analog materials.
If available, access to physical samples is described in the "WR CMG Sample Distribution Policy" at: <http://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html>
Primary access to the USGS/CMG Information Bank's digital data, analog data, and metadata is provided through... <http://walrus.wr.usgs.gov/infobank/>
This page accomodates a variety of search approaches (e.g., by platform, by region, by scientist, by equipment type, etc.).

Data format:

ASCII Size: 0.1

Network links:

<http://walrus.wr.usgs.gov/infobank/d/d196nc/html/d-1-96-nc.nav.html>

Activities:	by ID by Platform by Year by Region by Participant by Organization by Project/Theme with Incomplete IDs Disclaimer
Activity First Letter:	A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9
Virtual Globes:	Atlas (GE) Samples (GE) Moorings (GE) Illuminate Oceans (GE) Earthquakes (GE) Get GE InfoBank examples State Waters Chronology (GE) Gravity Base Stations (GE)

What does this data set describe?

Who produced the data set?

Why was the data set created?

How was the data set created?

How reliable are the data; what problems remain in the data set?

How can someone get a copy of the data set?

Who wrote the metadata?